Fiori and SAP Screen Personas Integration

We would like to simplify standard SAP screens using screen personas and integrate that into the Fiori Launchpad. Our system is following hub deployment where in fiori frontend is on the gateway and the backend is S/4 HANA for data. The question, where should we need to install the SAP Screen Personas add-on for screen simplification and flavor creation, on the frontend server or on the backend system?

My understanding is that the add-on need to installed on the backend and the application on LPAD configuration on the frontend should point to backend via system alias. Please correct me if I am wrong.

Regardless of how you set up your web dispatcher or Fiori launchpad, the PERSONAS add-on must always be installed on the backend where you want to modify screens. It cannot be installed on a gateway. Or, rather said, it can but then it works on the gateway instance only which is not what you'd want, I suppose.

I'm not experienced enough with the infrastructure for setting up the web dispatcher, so I rather wouldn't advise on that.